def v(s):
    if len(s) < 2:
        return 0
    return int(s[-1]) - int(s[0])

def va2(l, i):
    if len(l) <= 1:
        return 0
    v1 = l[i-1] - l[0]
    v2 = l[-1] - l[i]
    return v1 + v2

def groupSplit(group):
    mini = 1
    minv = va2(group, 1)

    for i in range(2, len(group)):
        tminv = va2(group, i)
        if tminv < minv:
            minv = tminv
            mini = i

    return mini, minv

def solve(l, k, d):
    if l == k:
        return 0
    d.sort(key=int)
    groups = [tuple([int(k) for k in d])]
    for _ in range(0, k - 1):
        mini = 0
        min_split_index, value = groupSplit(groups[mini])
        maxdiff = value - v(list(groups[mini]))
        for i, g in enumerate(groups[1:], start=1):
            if v(g) < maxdiff:
                continue
            split_index, value = groupSplit(list(g))
            tmindiff = value - v(list(g))
            if tmindiff < maxdiff:
                mini = i
                maxdiff = tmindiff
                min_split_index = split_index
        groups.append(tuple(sorted(groups[mini][:min_split_index])))
        groups.append(tuple(sorted(groups[mini][min_split_index:])))
        del groups[mini]
    return sum([v(s) for s in groups])

if __name__ == '__main__':
    l, k = map(int, input().split())
    print(solve(l, k, input().split()))